Figure 4.31. There is an AC generator on the left labeled V sub in. Its lower terminal is connected to the D terminal of a transistor equivalent circuit. The upper end of the generator connects to the G terminal. The D terminal connects to the bottom line of the circuit and the G terminal is open. There is a current source labeled G sub m V sub gs. Its lower terminal connects to the bottom line of the circuit. The arrow in the current source is pointing up. There is a resistor in parallel with the current source labeled r sub d. Both r and d are lower case. On the right the D terminal connects to the bottom line of the circuit. The S terminal connects to the top end of the current source and the resistor. Between the terminals is a label V sub O. Outside the circuit a resistor connects between the D and S terminals. The resistor is labeled R sub L, both R and L are upper case. End verbal description.